This project is concerned with the processing of visual information. Subjects take art in a variety of tasks. Some tasks require subjects to make semantic decisions about pictures and words. For example, they might indicate whether two pictures are members of a common category, or whether a picture (or word) is a member of some target semantic category. In another sort of task, a subject first learns about some visual array and is then tested on it. For example, the array might consist of fragments of some visual form, and the test might require the subject to indicate whether the fragments could be integrated to produce a given whole. Or the array might consist of a spatial map, and subsequent tests might ask questions about relative distances between points on the map. The foregoing tasks use response time as the principal dependent variable. In other tasks, the subject sees a list of visual forms and then takes a recognition test on them. Semantic or visual encoding of the forms is induced by instructions, and encoding effects are then assessed, using error data. In general, the data from these studies are used to address the following questions: (1) How are visually presented sttmuli retained? (2) What is the nature of the representation in long-term memory about categories of visual stimuli? (3) How do the memorial representations of visual information compare to corresponding verbal representations?